Efficient simulation models for correlated Nakagami-m fading channels are required for the development, performance evaluation and validation of diversity combining systems in general fading channels. We propose a theoretical explanation of the Nakagami-m distribution, as a natural extension of the Rayleigh fading model. In this model, a Nakagami random variable is viewed as the norm of an m-dimensional complex random vector. The elements of this m-dimensional random vector are orthogonal to each other, and have Rayleigh-distributed envelopes. Based on this decomposition approach, correlated Nakagami channel gains can be efficiently generated, given the specified correlation coefficients between the underlying Rayleigh processes